In Evolved Universal Terrestrial Radio Access (E-UTRA) systems, an enhanced Serving Mobile Location Center (e-SMLC) uses positioning related measurement results from a target user equipment (UE) to locate the UE. Cell-specific Reference Signals (CRS) measurements are utilized for enhanced Cell ID (e-CID), Radio Frequency Pattern Matching (RFPM), and Observed Time Difference Of Arrival (OTDOA) positioning methods. For e-CID, the UE reports UE Reception-Transmission (Rx-Tx) time difference, Reference Signal Received Power (RSRP), and Reference Signal Recieved Quality (RSRQ) to the network, but does not reportCell-specific Reference Signals (CRS) Signal to Interference plus Noise Ratio (SINR) (or Es/Iot). Without CRS SINR, the network cannot be aware of the real condition the target UE is experiencing, and therefore the positioning measurement results reported by the UE in a bad wireless condition (e.g., high interference condition) is likely to be used in UE location calculation in positioning server, which results in a positioning error.
For RFPM, the reported RSRP or RSRQ is used for fingerprint mapping. However, similar to the e-CID scheme, the UE reports the RSRP and RSRQ to the network but without CRS SINR (or Es/Iot), and therefore the network cannot distinguish which RSRP and RSRQ measurements are believable for positioning. If the network used the RSRP measurement results of relatively or substantially low SINR, the measurement error of this RSRP can be significant and degrade positioning performance. For OTDOA, the reported Reference Signal Time Difference (RSTD) is used for OTDOA positioning. However, the Positioning Reference Signal (PRS) SINRs of different cells are not provided to the network. If the e-SMLC uses all the reported RSTDs, the RSTDs from a relatively or substantially low PRS SINR cell can negatively impact positioning accuracy. Thus, considering the SINR condition for positioning calculation is beneficial to improve positioning accuracy.